<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div class="main as">
    </div>
</body>
<style>
    .main.as{
        background-color: blue;
        height: 500px;
        width: 500px;
        box-shadow: 10px 10px 10px 10px #B3C0D1;
    }
</style>
</html>